Electric resistance heating elements using metal alloy resistance wire have the advantage that the wire can be cold bent more or less sharply. The wire can be cold bent to form loops, zigzag shapes, etc., simplifying manufacture of the elements.
Molybdenum disilicide wire, exemplified by wire sold under the trademark "KANTHAL SUPER", can operate at higher temperatures than any metal alloy wire, but it is brittle when cold and requires heating to high temperatures for bending. This characteristic has not prevented successful commercialization of molybdenum disilicide hairpin elements formed by a single long loop of the wire and designed for relatively heavy-duty industrial use, with the necessary bend formed at the high temperature required. It has retarded the use of molybdenum disilicide wire in connection with the commercial manufacture of domestic heating appliances such as is exemplified by the cooking stove hot plate described by the U.S. Giler Pat. No. 3,912,905 where a heating grid formed by molybdenum disilicide wire looped back and forth in sinuous of zigzag formation is illustrated.
In all cases it is desirable to eliminate the necessity for heating molybdenum disilicide wire whenever it is necessary to form the wire into a loop requiring a relatively sharp bend from which mutually separated lengths of the wire extend and particularly when a number of loops are required by a single element such as in the case of a cooking stove hot plate.